4th order bandpass enclosure help

I'm trying to design a 4th order bandpass box for two audiopipe 15s but don't know which air space to use the subs I have call for 3cube ft each in a sealed box and 3.5 cubic ft each in a ported box. I have heard people say 2:1 ratio but is it off of total of 13 cubic ft or the seals or ported . I guess what I am asking is what cubic ft should I use for each sub sealed and what total cubic ft for the ported section and what size should the port be for say 32hz please help!!!

Re: 4th order bandpass enclosure help

Originally Posted by Audiopipe

It's actually going in a trunk of a Benz but has a custom fiberglass rear deck with a big blow threw

even if the trunk is really big, 2 15s 4th order in a trunk is kind of stretching it, unless you build it inside the trunk and take out the spare tire compartment. I wish you the best of luck though.
the 2:1 is a solid choice and gives you a pretty good handling and bandwidth. the 2.5 : 1 has the potential to be a lot more peaky depending on the tuning.

Re: 4th order bandpass enclosure help

If you're going for SPL in a 4th order you don't want tuning that low. In the low to mid 40s would be better for both your goals and your subs, as they will not play well at low frequencies without a shite tone af air behind them.

If you want to do it right, I would recommend downloading WinISD Beta and modeling the subs in a number of different boxes. If you can find a curve you like on that program, then build it.

But just trying different volumes at random or relying on rules of thumb ratios that do not take into account the characteristics of the individual drivers is the reason why 4th and 6th order enclosures have the reputation of being hard to design.